Search

The use of alternative fuels in diesel engines has been the subject of research that seeks new fuels to expand the energy matrix. The aim of this study was to evaluate the performance of the stationary engine with the use of mixtures of biodiesel from soybean and castor bean added to diesel (S500) in two proportions (25% and 40%), evaluating the torque, effective power observed and specific consumption. The five biodiesel mixtures of soybean (S) and castor bean (C) analyzed were: S100C0, S75C25, S50C50, S25C75 and S0C100, which were added to the diesel in proportions B25 and B40, totaling ten treatments, plus the control with diesel S500 (B7). The stationary engine was subjected to the rotations of 3000, 2700, 2400, 2100, 1800 and 1500 rpm. The performance of the engine was similar for all biodiesel mixtures of soybean and castor bean, and commercial diesel (B7). The B40 S100C0 and B40 S75C25 provide better performance in terms of effective power observed and torque at 2700 rpm. The highest effective maximum power (3000 rpm) was obtained with the use of B7 diesel. In the lower rotations, it was possible to identify a similar performance result of the biodiesel mixtures with the B7, in addition to providing better torque and consumption performance compared to the commercial diesel.

O segmento de papel e celulose é um dos mais importantes segmentos industriais eletrointensivos do país. As unidades industriais são intensivas tanto no uso de energia térmica quanto elétrica, nas diversas etapas da produção de celulose e posteriormente na fabricação de papel. Grande parte dessa demanda energética é suprida por combustíveis provenientes do próprio processo, como o licor negro e biomassa florestal, entretanto, em muitos casos as unidades não são autossuficientes em energia. A matriz energética dessa indústria se baseou, inicialmente, no suprimento através do óleo combustível, abundante e barato. Todavia, com as crises de petróleo e a recessão estabelecida no país na segunda metade da década de 70, ocorreram rápidas e significativas mudanças, motivadas pelo incentivo do uso do licor negro em caldeiras de recuperação química. O gás natural, com a exploração das bacias de Santos e Campos, bem como com a construção do Gasoduto Brasil-Bolívia, também se tornou uma boa opção energética para a substituição do óleo combustível. Nesse trabalho buscou-se analisar as possíveis trajetórias da matriz energética da indústria de papel e celulose brasileira, no horizonte de curto e médio prazo, assim como identificar os fatores de transformação no histórico da matriz e definir tendências para o mercado de combustíveis e para o desenvolvimento tecnológico associado ao uso dos produtos energéticos no setor. As principais mudanças na participação dos insumos energéticos dessa indústria se deveram não somente pela relação de preço, mas também associadas às políticas setoriais, como o incentivo à autoprodução de energia e aproveitamento de subprodutos para diminuir a dependência externa de combustíveis e energia elétrica. Investimentos no aumento de eficiência dos processos e a adoção de tecnologias avançadas na geração de energia levarão à menor dependência externa de combustíveis e energia elétrica. A elevação dos preços dos combustíveis fósseis, associada à formação pouco transparente do preço em mercados verticalizados, tem proporcionado um incentivo à ampliação do uso de biomassa na matriz energética. Além disso, diante das incertezas sobre a demanda futura de celulose,a competitividade da indústria de papel e celulose estará vinculada à diversidade nos produtos gerados, aplicando o conceito de biorrefinarias florestais e realizando os múltiplos aproveitamentos da biomassa em rotas tecnológicas distintas. Pulp and Paper is one of the most important energy intensity industries in Brazil. Industrial units are intensive in both use of thermal and electrical energy, in many processes during pulp and papermaking manufacturing. Much of this energy demand is supplied by fuel from process itself, such as black liquor and forest biomass; however, in many cases units are not self-sufficient in electricity. Initially, Pulp and Paper energy matrix was based on fuel oil supply, abundant and cheap. However, with oil crisis and Brazilian recession established in the second half of 70s, there were fast and significant changes, motivated by incentives of black liquor utilization in chemical recovery boilers. Natural gas, explored in Santos and Campos Basins, and also with the construction of Bolivia-Brazil gas pipeline, has become a good energy option for replacement of fuel oil supply. In this paper we have analyzed possible trajectories for Brazilian Pulp and Paper energy matrix, in a short and medium term, even as identified changing factors in matrix historical data and defined trends for fuel market and technological development associated with energy usage. Main changes in Pulp and Paper energy inputs share were explained not only by the price ratio, but also to sectorial policies, as self-generation incentives and utilization of byproducts to reduce dependence of external supply of fuel and electricity. Investments to increase process efficiency and adoption of advanced technologies in power generation will lead to less dependence on external supply. Rising fossil fuel prices, associated with anon-transparent price formation in vertical markets, has motivated an increase of biomass use in energy matrix. Moreover, given the uncertainty about pulp future demand and prices, Pulp and Paper competitiveness is related to products diversity, by applying forest biorefineries concept and performing biomass multiple utilizations in different technological routes.

Considered the best substitute for diesel, biodiesel can be blended with diesel in any ratio, bringing lots of environmental, economic and social advantages. Brazilian law Nº 11097/2005, proposes the introduction of biodiesel in to the Brazilian energy matrix, mixed with diesel at a minimum percentage of 2%. For consumers and sellers to be sure that the commercialized mixture of biodiesel:diesel contains the correct percentage, it is necessary to develop analytical methodologies to quantify the amount of biodiesel added. This work presents a fast, low-cost and simple methodology to determine the biodiesel proportion in mixtures of biodiesel:diesel, based on infrared spectroscopy.

This paper explores how Turkey’s politics and economy are affected by changes in global energy. To define which are the most relevant developments, the paper opens with an overview of the country's economic landscape. This analysis illustrates that energy, being the key driver behind its large current account deficit, represents a major point of vulnerability for the country. On this basis, the paper illustrates Turkey's energy matrix, an analysis that outlines the rising role of gas in the country's energy sector, both under the internal (i.e. growing share of the mix) and external (i.e. the country's potential role as regional gas hub) points of view. Finally, these issues are discussed with the aim of assessing the prospects for Turkey to turn gas into a geopolitical and economic asset for the country.

It has been very significant to visualize time series big data. In the paper we shall discuss a new analysis method called "statistical shape analysis" or "geometry driven statistics" on time series statistical data in economics. In the paper, we analyse the agriculture, value added and industry, value added (percentage of GDP) changes from 2000 to 2010 in Asia. We handle the data as a set of landmarks on a two-dimensional image to see the deformation using the principal components. The point of the analysis method is the principal components of the given formation which are eigenvectors of its bending energy matrix. The local deformation can be expressed as the set of non-Affine transformations. The transformations give us information about the local differences between in 2000 and in 2010. Because the non-Affine transformation can be decomposed into a set of partial warps, we present the partial warps visually. The statistical shape analysis is widely used in biology but, in economics, no application can be found. In the paper, we investigate its potential to analyse the economic data.

Este artigo discute a realidade energética no âmbito dos BRICS, com especial atenção às energias renováveis. Sob tal perspectiva, o Brasil emerge com papel destacado na coalizão, sendo considerado um dos países mais descarbonizados do mundo, pioneiro em bioenergia e um dos líderes globais em geração eólica e hidrelétrica. Por outro lado, o carvão ocupa um espaço considerável na matriz energética da Áfri ca do Su l, China e Índia. Ademais, o bloco ainda conta com o maior produtor de petróleo cru do mundo: a Rússia. Levando em consideração as potencialidades e os desafios de cada país no tocante ao assunto, esta pesquisa se estrutura em torno de dois eixos principais: avaliar como as fontes renováveis permeiam os acordos bilaterais firmados pelo Brasil na área de energia com os “RICS”; e entender como o debate está caracterizado nas declarações conjuntas das cúpulas do bloco. A metodologia utilizada envolveu a construção de um banco de dados original, bem como a aplicação de técnicas de estatística descritiva e análise de conteúdo. Os resultados apontam que China e Rússia dominam, de longe, a pauta ene rg&eacut e;tica bilateral do Brasil com os RICS e que o governo Lula foi, desde a redemocratização, o mais ativo em termos de quantidades de atos internacionais referentes à energia firmados com esses parceiros. Os achados também indicam alguns pontos de intersecção entre as pautas bilaterais e as posições conjuntas adotadas nas declarações de cúpula, a despeito de não ter havido um aumento dos acordos sobre energia após o estabelecimento dos BRICS., This paper discusses the energy reality within the BRICS, with special attention to renewable energies. From this perspective, Brazil emerges with a prominent role in the coalition, being considered one of the most decarbonized countries in the world, a pioneer in bioenergy and one of the global leaders in wind andhydroelectric generation. On the other hand, coal occupies a considerable space in the energy matrix of South Africa, China and India. In addition, the has the largest crude oil producer in the world: Russia. Taking into consideration the potential and challenges of each country regarding this matter, this research is structured around two main axes: to evaluate how renewable sources permeate the bilateral agreements signed by Brazil in the area of energy with the “RICS”; and understand how the debate is characterized in the summits joint declarations. The methodology used involved the construction of an original database, as well as the application of descriptive statistics and content analysis techniques. The results indicate that China and Russia dominate Brazil's bilateral energy agenda with the RICS and that the Lula administration has been, since the redemocratization, the most active in terms of the number of International energy acts signed with these partners. The findings also indicate some points of intersection between the bilateral agenda and the joint positions adopted in the summit declarations, although there was no increase in energy agreements after the establishment of the BRICS.

An on-load tap changer (OLTC) is one of the most error-prone parts in the transformer. The stability of the entire power system will be greatly threatened if the OLTC fails. It is necessary to diagnose the mechanical fault of OLTCs. At the same time, the mechanical fault signals are not easy to collect during practical application. It is desirable to have indicators that help to access the condition of the OLTC with a small number of fault samples. This paper describes a strategy for distinguishing different mechanical diagnostics of OLTCs based on dynamic time warping. By synchronization, framing, and Fourier transform, the signal can be represented by an energy matrix, which can be used to distinguish different conditions of the OLTCs and shows the severities of the fault. Some simulated experiments are designed and in order to make the simulations close to reality, all experiments are taken in a tank which is filled with transformer oil. These experiments demonstrate that the proposed approach can effectively diagnose different OLTC faults under different fault severities.

This paper proposes as a principal objective shows that the situation of oil prices in the initial four months of 2020 in Colombia and in general in medium oil producing countries implies the opportunity to rethink the production structure and the energy matrix too. The causes of this drop in oil prices are presented and discussed, such as world demand, pressured in the months of March and April by the COVID-19 situation, the self-sufficiency of the United States and the energy transition in China. Some statistical data are then presented to reinforce the opportunity argument represented by the drop in prices of both fossil and alternative energy. At the same time, the environmental implications of exploiting unconventional oil reserves are questioned for the need of exploitation with non-conventional techniques such as fracking. In the end, a return to development banks is proposed to promote both economic diversification and the energy transition. &nbsp

Fossil fuels still prevail over other energy sources in the world’s consumption energy matrix. Thus, oil transportation and operations over maritime routes have been in high demand for a long time. Although oil spill accidents caused by these activities have reduced significantly over the last few decades, they still cause great concern. From this perspective, this paper presents simulation analyses of oil spill case studies using TELEMAC-3D hydrodynamic model coupled with an oil model. Hence a location susceptible to such accidents was selected and three real oil spills were simulated, for each of which there were official technical monitoring reports available. The obtained results contribute to the knowledge of oil pollution susceptibility in environmentally sensitive areas, as well as provide information concerning oil slick behaviour. Additionally, similarities between the modelled results and the technical reports were confirmed. These findings are useful for contingency planning and responding to these probable accidents.

This paper aims to address the necessity of the international community regarding the reformulation of energy policies after the oil shock (70's) to enable the diversification of its energy matrix and foster prosperous relations in this area. Thus, will approach the Brazilian energy policy through the concept of energy security that, although is often confused with energy independence, has a broader scope of analysis that overflows to a wide variety of sectors and dimensions beyond energy itself.

This paper provides empirical evidence of a long-run environmental Kuznets curve (EKC) for Ecuador from 1971 to 2011. Using the autoregressive distributed lag bounds testing approach, we do not just estimate the effect of economic growth on CO2 emissions but also the effect of energy consumption on this one. The effects of all variables have the expected signs. In addition, we test for Granger causality among the variables using an error correction model. Only GDP granger causes energy consumption in the short-run. The results have several policy implications that are consistent with the recent environmental policy of the government

Renewable energy sources have a key role in the energy mix because of their impact on Greenhouse Gases emissions, national energy security, among others. In this context, this paper examines comparatively, under a systemic and multidimensional approach, the policies that have introduced renewable energy in the electric power generation in Argentina, Brazil and Uruguay. The results show that Argentina has had a low performance in these policies in comparison to Brazil and Uruguay, due to failures in the promotion mechanisms and institutional designs., Las fuentes renovables de energía poseen un rol esencial en el mix energético de un país, por su impacto en las emisiones de gases de efecto invernadero, la seguridad energética, entre otros. En este contexto, el objetivo de este artículo es analizar comparativamente, bajo un abordaje sistémico y multidimensional, las políticas que se han desarrollado para promover las energías renovables en la generación eléctrica en la región sudamericana, en particular en Argentina, Brasil, y Uruguay. Los resultados muestran que Argentina ha tenido un desempeño muy pobre comparado con Brasil y Uruguay, debido a la existencia de fallas en los marcos de promoción y en los diseños institucionales.

This work tries to determine whether it is possible to stabilize CO2 emissions under a rapid increase of Gross Domestic Product in a medium term. The paper is an effort to study in detail how changes in the driving forces of the economy affect CO2 emissions. We study the case of Venezuela for the period 1980–2025, using the methodology proposed by Robalino-Lopez et al. (2014, 2013) [1] , [2] , which is based on an extension of the Kaya identity and on a GDP formation approach that includes the effect of renewable energies. We test the environmental Kuznets curve (EKC) [3] hypothesis in a coming future under different economic scenarios considering, therefore, not only past data but also projections for the coming years. We use cointegration techniques [4] and the Jaunky (2011) [5] specification to test the fulfillment of the EKC hypothesis in Venezuela. Our predictions show that Venezuela does not fulfill the EKC hypothesis, but however, the country could be on the way to achieve environmental stabilization in the medium term. This stabilization could be accomplished combining economic growth with increasing use of renewable energy, appropriated changes in the energy matrix, and in the productive sectoral structure.

The Brazilian electricity energy matrix is essentially formed by hydraulic sources which currently account for 70% of the installed capacity. One of the most important characteristics of a generation system with hydro predominance is the strong dependence on the inflow regimes. Nowadays, the Brazilian power sector uses the PAR(p) model to generate scenarios for hydrological inflows. This approach does not consider any exogenous information that may affect hydrological regimes. The main objective of this paper is to infer on the influence of climatic events in water inflows as a way to improve the model’s performance. The proposed model is called “causal PAR(p)” and considers exogenous variables, such as El Niño and Sunspots, to generate scenarios for some Brazilian reservoirs. The result shows that the error measures decrease approximately 3%. This improvement indicates that the inclusion of climate variables to model and simulate the inflows time series is a valid exercise and should be taken into consideration.

The energy matrix is a useful tool for understanding the trends of production and consumption in a country and for evaluating long-term energy policies. This paper presents a behavioral simulation model of the evolution of Chile’s energy matrix. The model is developed and calibrated by considering a dynamic substitution of energy sources. Chile’s stated policy is to become less dependent on imported fossil fuels, to increase security of supply and improve the environment. The simulation experiments show that the energy matrix is very robust with regards to external fuel prices and changes in investment cost. Thus, in order to be able to observe changes in the composition of the energy matrix, there is a need for strong intervention by the regulator, or the government, to provide incentives for renewables.

The Ministry of Energy and Mines of Nicaragua (MEM) is planning to launch in 2013 a massive replacement program of 2 million incandescent lamps with compact fluorescent lamps (CFLs). This paper explores the expected impacts on a 10 year basis (2013–2023) using cost/benefit analysis for consumers, utility and society. Market conditions for introduction of a 7 W LED in the residential sector were also analyzed. Three prospective scenarios were considered in order to estimate the impact of CFLs penetration. Finally, the analysis is complemented with laboratory tests for eight lamps—three CFLs of the pilot program batch and one incandescent lamp 75 W; three CFLs and a 7 W LED available in the national market. Results supports that for countries like Nicaragua with an energy matrix still dependent on imported petroleum, energy efficiency programs are especially positive in economic and environmental terms. However, it is necessary to implement and to test CFLs programs requirements about high power factor (PF≥0.9) and low total harmonic distortion (THD≤20%).

The last 20 years have presented a favorable scenario for the incorporation of renewable energy sources into the energy matrix of developing countries. This situation promoted grid connected photovoltaic generation systems (GCPVS) to become one of the main protagonists in this new concept of energy matrix. In some developing countries the use of such systems is in its beginning. Promotion policies and technical as well as regulatory conditions for their installation have just started to be defined. In this context, there exists in Argentina a legal and regulatory framework for the implementation of large photovoltaic plants but there is a lack of such legal framework for distributed generation (DG) by means of grid connected photovoltaic into the medium and low voltage distribution networks. This situation led research centers, together with private and provincial Energy Agencies to install pilot systems in order to identify and characterize their impact on the low voltage distribution network, taking into account the local grid capacity and characteristics of each province. In this paper the implications of different degrees of penetration of solar photovoltaic power generation evaluated using technical parameters of the network is presented. A set of examples of residential users connected to a distribution substation in the city of Corrientes is analyzed by means of a simulation using real grid data with the incorporation of GCPVS generation. The simulation results show that both the level of penetration of GCPVS systems as well as location where these distributed energy sources should couple to the distribution grid must be carefully assessed to maximize the benefits of the inclusion of distributed generation in urban environments.

The EPR g factors g|| and g⊥ for two tetragonal Ce3+ centers T1 and T2 in Ce3+-doped cubic fluorperovskites KMgF3 and BaLiF3 are calculated from the complete diagonalization (of energy matrix) method (where all the Kramers doublets within the ground and excited multiplets 2F5/2 and 2F7/2 are contained). The calculations show that the simple method of calculating g factors (where only the doublets within the ground multiplet 2F5/2 are considered) used in the previous papers cannot give the correct signs of crystal-field parameter B 2 0 and hence the reasonable defect models for these tetragonal Ce3+ centers (in fact, physically, these defect models are inconsistent). The new and consistent defect models for these Ce3+ centers are suggested as follows: in KMgF3:Ce3+, centers T1 and T2 are the substitution of Ce3+ for K+ with a nearest interstitial F− and, respectively, with and without a nearest K+ vacancy (VK) along C4 axis, and in BaLiF3:Ce3+, centers T1 and T2 are the substitution of Ce3+ for Ba2+ with, respectively, a nearest interstitial F− and a nearest Ba2+ vacancy along C4 axis because of charge compensation. Based on these defect models and by considering the orbit reduction effect due to the covalence of Ce3+–F− bonds, the g factors of these tetragonal centers are explained reasonably. The results (in particular, the approximations of the defect structural data for these tetragonal centers) are discussed.

A produção de biocombustíveis tem sido amplamente debatida no Brasil e no ano de 2014 foi criado o Programa Nacional de Uso e Produção de Biodiesel (PNPB). Este programa busca incentivar uma maior participação de energias renováveis na matriz energética brasileira, com o objetivo de implementar de forma sustentável, técnica, e econômica, a produção e uso do Biodiesel. Além do enfoque na inclusão social e no desenvolvimento regional, via geração de emprego e renda. No panorama nacional, o Estado do Tocantins destaca-se por dispor de uma vasta disponibilidade de terras e apresentar boas perspectivas logísticas devido a implantação de novos modais de transporte. A agricultura familiar é considerada o grande propulsor do agronegócio com, aproximadamente, 45 mil propriedades rurais. Neste contexto, o presente trabalho visa demonstrar os fatores que contribuem com o cenário da produção de biodiesel no Estado do Tocantins.Palavras-chave: Produção; Sustentabilidade; Agricultura familiar; Biocombustíveis.ABSTRACTBiofuel production has been widely debated in Brazil and in 2014 was created the National Program for Production and Use of Biodiesel (NPPB). This program encouraging a greater share of renewable energies in the Brazilian energy matrix, aiming to implement sustainably , technical , and economic , production and use of biodiesel, with a focus on social inclusion and regional development by generating employment and income . On the national scene, the State of Tocantins is distinguished by having a wide availability of land and has good prospects because of logistical deployment of new modes of transportation. Family farming is considered the major driver of agribusiness with approximately 45000 farms. In this context, this paper aims to demonstrate the factors that contribute to the scenario of biodiesel production in the state of Tocantins.Keywords: Production; Sustainability; familiar Agriculture; Biofuels.

O artigo propõe e avalia três metodologias para estimar matrizes energéticas nacionais mais desagregadas a partir dos dados da matriz insumo-produto (MIP). Para avaliar os resultados, foram construídas três matrizes insumo-produto híbridas. As análises de correlação e de acuidade dos multiplicadores, índices de ligação setoriais, requerimentos de energia e emissões de CO2 mostraram convergência de resultados nos métodos Base BEN e Base MIP Ajustada. Conclui-se, portanto, que o uso de coeficientes insumo-produto, como ponderadores de expansão do consumo setorial de energia, permite estimar matrizes energéticas consistentes e que são válidas as análises estruturais da economia realizadas com base nelas. This paper proposes and evaluates three methods for estimating more disaggregated national energy matrices from input-output matrix (IPM) data. To evaluate the results three hybrid input-output matrices were built. Correlation and acuity of multipliers analyses, binding sectorial indices, energy requirements and CO2 emissions showed convergence results in BEN Base and Base Adjusted MIP methods.We conclude, therefore, that the use of input-output coefficients as weights for sectorial energy consumption expansion allows to estimate consistent energy matrices and that the structural analyzes of the economy based on them are valid.

The use of biodiesel in Brazil was consolidated after 2005, when the Federal Government established a time frame to insert biodiesel in Brazilian energy matrix and so that a 5% biodiesel in diesel blend (B5) has been mandatory since January, 2010. Now the attention turns to blends with higher level of biodiesel and vehicle and engine assemblers, fleet owners and other private and governmental entities are conducting extensive researches on the subject. This paper evaluates the use of a 20% biodiesel in diesel blend (B20) in light duty vehicles with EURO III and EURO IV technologies and its impact on the durability of engines and systems. Vehicles of both technologies endured a field test during which they accumulated 100.000 km in urban and road circuits. They were then evaluated according to the deterioration of performance and pollutants emissions and wear of parts and components. Results were compared to those obtained in similar vehicles using a B5 blend as fuel, subjected to the same test conditions. Engine wear and deposit formation on rings, pistons and cylinders were evaluated by the manufacturers through visual and dimensional inspections, and were found compatible to the use of the engines; there was no significant differences between the groups. Track performance and chassis dynamometer emissions tests showed that EURO IV vehicles were less influenced by the use of differentiated fuels, with vehicles that run on B20 during the field test showing results statistically equivalent to those that run on B5. On the other hand, EURO III vehicles that run on B20 had performance losses up to 7% when compared to those that run on B5. They could not be evaluated according to their emissions.

This paper aimed makes a bibliographic review of how the electric energy is generated by hydropower plants and the environmental injuries by this kind of enterprise. The hydraulic energy is produced through the power of water movement, by hydropower plants. The main factors that influence the generation of this energy are: river’s flow, quantity of available water in a determined period of time and the difference in level, being them naturals, like waterfalls, or created artificially. Although of a significantly portion of contribution in world energy matrix, hydraulic energy causes several socioeconomic impacts, as great areas waterlogging injuring flora, fauna and the community that lives around the river. However this impacts are important whereas can be easily corrected, with a good environmental and social assistance, and a part of the investment coasts destined to it. Before the implantation of this enterprise, it’s important make and action plan aiming reduce

This paper examines the influence of parametric uncertainties on the optimal sensor placement methodologies for the modal analysis of a truss bridge. Four classical sensor location methodologies are employed: two based on the Fisher information matrix and the other two based on energy matrix rank optimization. Young's modulus, mass density and cross sectional dimensions are considered as uncertain parameters. The independent and cumulative effects of these uncertain variables on the sensor placement are studied. The optimal locations of sensors under parametric uncertainty are assessed with three different criteria: the Fisher matrix determinant, the modal assurance criterion error and the condition number. Furthermore, the robustness of this configuration is investigated for the case of random and bias errors. The numerical results show the parametric uncertainties have significant influence on the optimal sensor configuration of a truss bridge.

The paper demonstrates how it is organized production chain of natural gas in Rio Grande do Norte and highlights some prospects for this sector. The study is backed by elements to understand the process of innovation as the driving force of capitalist dynamics as well as the features of the Brazilian economy in the years 1990 and 2000 that indicated the development of natural gas production in the energy matrix Brazil. It was found that the state has potiguar possibilities for structuring an energy based on elements from the region and with prospects of becoming self-sufficient in electricity, where natural gas has a share of participation in this segment. The automotive and industrial are the biggest consumers of this input. With emphasis on the textile industry. Signaling to a broad horizon of supply, this sector will depend on their investments in research and Deficient, and the policy adopted by government to develop the consumer market O trabalho demonstra como está organizada a cadeia produtiva de gás natural no Rio Grande do Norte e ressalta algumas perspectivas para este setor. O estudo está respaldado pelos elementos que permitem compreender o processo de inovação enquanto força motriz da dinâmica capitalista, bem como os aspectos que caracterizam a economia brasileira nos anos de 1990 e 2000 e, que sinalizaram para o desenvolvimento da produção de gás natural na matriz energética brasileira. Constatou-se que o estado potiguar tem possibilidades de estruturar uma matriz energética embasada em elementos da própria região e com perspectivas de se tornar auto-suficiente em energia elétrica, onde o gás natural tem uma parcela de participação neste segmento. O setor automotivo e industrial são os maiores consumidores desse insumo. Com destaque para a indústria têxtil. Sinalizando para um horizonte amplo de oferta, este setor dependerá de investimentos e pesquisas em sua infraestrura, e da política adotada pelo governo para desenvolver o mercado consumidor

Part II . The solution of the Schrodinger equation by means of the variation principle and a discrete basis leads to a certain secular equation. In a previous paper (Part I), it was shown that, if this equation is handled by a partitioning technique, a generalization of the Schrodinger-Brillouin formula is obtained. The procedure contains an inverse matrix, and it is shown here that, if in the expression for the wave function this matrix is approximated to the n th order, the corresponding matrix in the expectation value for the energy is approximated to order (2 n + 1). This gives a simple derivation and generalization of the Brillouin-Wigner theorem. The connection between the variation principle and perturbation theory is further discussed. Part III . The solution of the Schrodinger equation by means of the variation principle and a discrete but not necessarily orthonormal basis is studied in the case when the Hamiltonian H = H ( α ) is a function of a parameter α. The coefficients in the power series expansions in α of the wave function and the energy are explicitly determined in the form of expectation values, and the connection with the conventional Schrodinger theory is discussed.

The opportunity for renewable energy production in developing countries is a theme of high relevance within the context of climate change. In this paper we explore the production of electricity in Brazil and investigate the potential for sustainable biomass energy production. This is explored in a GIS system (1) establishing the demand centers or regions (energy demand factor), (2) checking if they can be served by existing capacity and transmission (transmission lines factor), (3) deciding on new generation and whether it will an island or the main grid connection (power plants factor), (4) locating the power plant subject to the potential biomass supply accepting the environmental constraints (land use and environmental preservation factors). Results show that even though large areas have a potential for biomass energy production, the lack of investments in technological improvements and changes in the system status quo result in a system that does not progress towards of becoming a cleaner, safer and less dependent on climatic factors. We conclude that biomass has the potential to grow as a source of renewable and clean energy. This potential can be explored by conserving respecting the environment and encouraging the creation of decentralized systems, thereby making Brazil a key player in the climate change targets in the coming years. Brazilian research incentive program Science Without Borders

This paper explores the relation between business sustainability, both linked to financial profit as well as to relations with local organizations, and the environment, in a context of an internationalized economy such as the Chilean economy. Likewise, it analyzes recent conflicts originated in Chile for energy supply and the difficulties in defining an energy matrix. Finally, the article analyzes the influence of ecological ethics in the preservation of the high diversity ecosystems in the South of Chile, facing the business development and the specific energy projects. Sustentabilidade empresarial, seguranca energetica e etica ambiental no Chile Resumo: O artigo explora a relacao entre sustentabilidade empresarial —associada tanto a rentabilidade financeira como as relacoes com coletivos locais— e o meio ambiente, no contexto de uma economia internacionalizada como a chilena. Do mesmo modo, analisa conflitos recentes originados no Chile para o provimento de energia e as dificuldades na definicao de uma matriz energetica, e, finalmente, a influencia da etica ecologica para a preservacao dos ecossistemas de alta biodiversidade no sul do Chile, frente ao desenvolvimento empresarial e aos projetos energeticos, especificamente.